Whenever a CAFC panel suggests that there is a doctrine of equivalents, it’s like a sighting of the Yeti or the Loch Ness monster. Usually, they are just teasing with the possibility, writing about it in some non-final appeal – which later returns and the DOE then is slaughtered.
Thus it is with today’s panel ruling in Regents v. Dakocytomation, the 2-1 finding that the patentee, who made a narrowing amendment to overcome a prior art rejection, was wronged by the erroneous lower court determination that the presumption of prosecution history estoppel could not be rebutted. And, you thought there was no ‘flexible bar’ when you narrowed and overcame.
Fine for now, but one has to think that this bunny will go back into the hat, this worm will turn, and the case for infringement by equivalents will not succeed on remand or on a 2nd appeal. Today though, the DOE was spotted, its shadow presumed to be rebuttable, meaning perhaps, there’ll be at least six more weeks of cases denying that the DOE even exists.